Monolithic polymer composition having a releasing material

ABSTRACT

The present invention includes processes and resulting structures for producing a modified polymer having interconnecting channels. The interconnecting channels act as controlled transmission passages through the polymer. A hydrophilic agent is blended into the polymer so that it is distributed within the polymer. In one embodiment, a releasing material is blended into the polymer so that the releasing material is distributed within the product. The product is solidified so that the hydrophilic agent forms passages in the product through which a desired composition is communicable to the releasing material that is entrained within the product. The solidified product may be used to form a desired shaped article such as plug type inserts and liners for closed containers, or it may be formed into a film, sheet, bead or pellet.

RELATED APPLICATION

This application is a continuation-in-part of U.S. Ser. No. 09/087,830,filed May 29, 1998, now U.S. Pat. No. 6,124,006, which in turn is acontinuation-in-part of U.S. Ser. No. 08/812,315, filed Mar. 5, 1997,now U.S. Pat. No. 6,130,263, which in turn is a continuation-in-part ofU.S. Ser. No. 08/611,298, filed on Mar. 5, 1996, now U.S. Pat. No.5,911,937, which in turn is a continuation-in-part of U.S. Ser. No.08/424,996, filed Apr. 19, 1995, now abandoned.

FIELD OF THE INVENTION

This invention generally relates to monolithic compositions comprising awater-insoluble polymer, a hydrophilic agent and a releasing material.In one embodiment, the present invention relates to modified polymersblended with one or more releasing materials to form a releasingmaterial entrained polymer. The invention further relates to anentrained polymer that includes means by which the releasing materiallocated within interior portions of the polymer structure are exposed toconditions that are exterior to the polymer body. In one embodiment, theentrained polymer of the present invention is useful in the manufactureof containers and packaging for items requiring controlled environments.

BACKGROUND OF THE INVENTION

There are many items that are preferably stored, shipped and/or utilizedin an environment that must be controlled and/or regulated. For example,in the moisture control area, containers and/or packages having theability to absorb excess moisture trapped therein have been recognizedas desirable. One application in which moisture absorbing containers aredesired is for the shipment and storage of medications whose efficacy iscompromised by moisture. The initial placement of medicines into asealed moisture free container is usually controllable. Furthermore, thecontainer for the medicine is selected so that is has a low permeabilityto moisture. Therefore, the medication will normally be protected frommoisture until it reaches the end user. Once the medicine is received bythe customer, however, the container must be repeatedly opened andclosed to access the medication. Each time the container is opened andunsealed, moisture bearing air will most likely be introduced into thecontainer and sealed therein upon closure. Unless this moisture isotherwise removed from the atmosphere or head space of the container, itmay be detrimentally absorbed by the medication. For this reason, it isa well known practice to include a desiccating unit together with themedication in the container.

Other items, electronic components may require reduced moistureconditions for optimal performance. These components may be sealed incontainers, but excess moisture that is initially trapped therein mustbe removed. Furthermore, the housings may not be completely moisturetight, and moisture may be allowed to seep into the container. Thismoisture must also be retained away from the working components. Forthese reasons, it is important to include a desiccating agent within thehousing for absorbing and retaining excess moisture. Because of thedelicacy of many of the components that are to be protected from themoisture, it is important that the desiccant used not be of a “dusting”nature that may contaminate and compromise the performance of thecomponents. Therefore, it has been recognized as advantageous to exposea desiccating agent to the interior space of such containers, while atthe same time shielding the working components from actual contact withthe desiccating material, including desiccant dust that may be producedtherefrom.

In other instances, moisture may be released from items that have beenplaced in containers or sealed in packaging wrap for shipping and/orstorage. Prime examples of such items are food stuffs-that releasemoisture during shipping and storage. In the instance of containers thatare sealed and substantially impermeable to moisture, the releasedmoisture will remain within the container. If not removed, this releasedmoisture may have ill effects on the very item that released themoisture. It has been found that a substantial amount of moisture isreleased from certain food products within the first forty-eight (48)hours after manufacture and packaging. This released moisture willremain until removed. If the moisture is not removed shortly after itsrelease, it may cause the food to degrade into a condition that is notsaleable. In these cases, desiccants may be included together with thecontained items to continually absorb the released moisture until theproduct is unpacked. In this way, a relatively dry environment ismaintained about the stored item.

SUMMARY OF THE INVENTION

The present invention discloses both a structure and a method by whichinterconnecting channels are established throughout the composition.These interconnecting channels communicate the entrained releasingmaterial to the appropriate areas of the exterior of the composition ina manner that permits the desired property to migrate from outside theplastic structure to interior locations where the releasing material ispositioned. Furthermore, these interconnecting channels through whichthe desired property is permitted to travel are occupied by hydrophilicagents (e.g., channeling agents) that control the transmission rate intothe composition. The hydrophilic agents are used to act as bridges fromthe surface of the composition inwardly to the releasing materialpositioned within the composition.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a plug, insert, or tablet constructedfrom the composition of the present invention showing, in an exaggeratedscale, the openings of the interconnecting channels at the exteriorsurface of the plug.

FIG. 2 is an exaggerated, cross-sectional view of a solidified plugformed from a water-insoluble polymer having a hydrophilic agent and areleasing material blended therewith.

FIG. 3 is an exaggerated cross-sectional view of a portion of acontainer having the composition of the present invention formed into aplug insert located in the bottom of a container constructed from apolymer that acts as a transmission rate barrier.

FIG. 4 is an exaggerated cross-sectional view of a portion of acontainer the composition of the present invention formed into a plugthat has been comolded into the bottom of a container that isconstructed from a polymer that acts as a transmission rate barrier.

FIG. 5 is an exaggerated cross-sectional view of a portion of acontainer the composition of the present invention formed into a linerinsert located within the interior of a container constructed from apolymer that acts as a transmission rate barrier.

FIG. 6 is an exaggerated cross-sectional view of a portion of acontainer having the composition of the present invention formed into aliner that has been comolded at the interior of a container that isconstructed from a polymer that acts as a transmission rate barrier.

FIG. 7 is an exaggerated cross-sectional view of the composition of thepresent invention formed into a sheet located adjacent to a barriersheet constructed from a polymer that acts as a transmission ratebarrier.

FIG. 8 is an exaggerated cross-sectional view the composition of thepresent invention formed into a sheet that has been comolded at aninterior of a barrier sheet so that the products are integrally moldedtogether and comprise one unified laminate.

FIG. 9 is a graphical view of a swelling and weight loss analysis ofthree film samples: Film #2, Film #3 and Film #4.

FIG. 10 is a graphical view of a DSC curve of a sample of 100%polyglycol.

FIG. 11 is a graphical view of a DSC curve of a sample of Film #4.

FIG. 12 is a graphical view of a DSC curve of a sample of Film #5.

FIG. 13 is a graphical view of an DSC curve of a sample of Film #6.

FIG. 14 is a graphical view of a DSC curve of a sample of Film #7.

FIG. 15 is a graphical view of a DSC curve of a sample of Film #2 in apre-incubation state.

FIG. 16 is a graphical view of a DSC curve of a sample of Film #2 in apost-incubation state.

FIG. 17 is a graphical view of a DSC curve of a sample of Film #3 in apre-incubation state.

FIG. 18 is a graphical view of a DSC curve of a sample of Film #3 in apost-incubation state.

FIGS. 19a-c are scanning electron photomicrographs of a film sample ofFilm #4.

FIGS. 20a-c are scanning electron photomicrographs of a film sample ofFilm #5.

FIGS. 21a-c are scanning electron photomicrographs of a film sample ofFilm #6.

FIGS. 22a-d are scanning electron photomicrographs of a film sample ofFilm #3.

FIGS. 23a and 23 b is a graphical view of showing the precent moisturegain per weight of molecular sieve at 10% Rh and 72° F. and 20% RH and72° F., respectively.

Among those benefits and improvements that have been disclosed, otherobjects and advantages of this invention will become apparent from thefollowing description taken in conjunction with the accompanyingdrawings. The drawings constitute a part of this specification andinclude exemplary embodiments of the present invention and illustratevarious objects and features thereof.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousforms. The figures are not necessarily to scale, some features may beexaggerated to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the present invention.

It has been discovered that certain compounds, which are referred toherein as hydrophilic agents (e.g., channeling agents), may be combinedwith a water-insoluble polymer that is used in the formation of shapedarticles. In practice, in one embodiment the water-insoluble polymerbase into which the hydrophilic agent is blended includes, as examples,any polyethylene and polypropylene.

In one embodiment, a releasing material and hydrophilic agent are addedto the water-insoluble polymer when the polymer is in a molten state orbefore the polymer is in the molten state, so that the material andhydrophilic agent may be blended and thoroughly mixed throughout thepolymer to insure that the blend is uniformly mixed before reaching themelt phase. For example, such a technique is useful when the releasingmaterial, hydrophilic agent and polymer are all powders.

In another embodiment, the hydrophilic agent and polymer are mixed priorto adding the releasing material. The hydrophilic agent is added eitherbefore the polymer is in the molten state or after the polymer is in themolten state. For example, the releasing material may be added to thepolymer during the thermal process of forming sheets.

After thorough blending and processing, following by cooling, thehydrophilic agent forms interconnecting channels that act astransmission communicating passages throughout the polymer. In addition,the composition of the present invention is monolithic and thewater-insoluble polymer, hydrophilic agent and releasing material form athree phase system.

For purposes of the present invention, the term “phase” means a portionof a physical system that is uniform throughout, has defined boundariesand, in principle, be separated physically from other phases. The term“interconnecting channels” means channels that penetrate through thewater-insoluble polymer and that may be interconnected to each other.The term “water-insoluble polymer” means a polymer having a solubilityin water below about 0.1% at 25° C. and atmospheric pressure. The term“hydrophilic agent” is defined as a material that is not substantiallycross-linked and that has a solubility in water of at least about 1% at25° C. and atmospheric pressure. Suitable hydrophilic agents include“channeling” agents. The term “monolithic composition” means acomposition that does not consist of two or more discrete macroscopiclayers. Accordingly, a “monolithic composition” does not include amulti-layer composite. Moreover, for purposes of the present invention,the term “melting point” is defined as the first order transition pointof the material determined by DSC. The term “not mutually soluble” meansimmiscible with each other.

In one embodiment, suitable hydrophilic agents of the present inventioninclude polyglycols such as poly(ethylene glycol) and poly(propyleneglycol) and mixtures thereof. Other suitable materials include EVOH,glycerin, pentaerithritol, PVOH, polyvinylpyrollidine, vinylpyrollidoneor poly(N-methyl pyrollidone) and saccharide based compounds such asglucose, fructose, and their alcohols, mannitol, dextrin and hydrolyzedstarch being suitable for the purposes of the present invention sincethey are hydrophilic compounds.

In another embodiment, suitable hydrophilie agents of the presentinvention may also include any hydrophilic material wherein, duringprocessing, the hydrophilic agent is heated above its melt point uponmelt mixing, and subsequently upon cooling separates from the polymer toform the interconnecting channeled structure of the present inventionand a three phase system of a water-insoluble polymer, hydrophilic agentand a releasing material.

The present invention may be employed with a variety of releasingmaterial. Such material may comprise any suitable form which willrelease dispersant to surrounding atmosphere, including solid, gel,liquid, and in some cases a gas. These substances can perform a varietyof functions including: serving as a fragrance, flavor, or perfumesource; supplying a biologically active ingredient such as pesticide,pest repellent, antimicrobials, bait, aromatic medicines, etc.;providing humidifying or desiccating substances; delivering air-borneactive chemicals, such as corrosion inhibitors; ripening agents andodor-making agents, etc.

The biocides of the present invention may include, but are not limitedto, pesticides, herbicides, nematacides, fungicides, rodenticides and/ormixtures thereof. In addition to the biocides, the covering of thepresent invention can also release nutrients, plant growth regulators,pheromones, defoliants and/or mixture thereof.

The incorporation of a quaternary ammonium compound, not only functionsas a surfactant but also imparts to the surface of the manufacturedproduct aseptic properties or establishes conditions for reducing thenumber of microbial organisms, some of which can be pathogenic. Numerousother antimicrobial agents, such as benzalkonium chloride and relatedtypes of compounds as hexachlorophene, may also be used.

Other releasing materials include fragrances, including natural,essential oils and synthetic perfumes, and blends thereof. Typicalperfumery materials which may form part of, or possible the whole of,the active ingredient include: natural essential oils such as lemon oil,mandarin oil, clove leaf oil, petitgrain oil, cedar wood oil, patchoulioil, lavandin oil, neroli oil, ylang oil, rose absolute or jasminabsolute; natural resins such as labdanum resin or olibanum resin;single perfumery chemicals which may be isolated from natural sources ofmanufactured synthetically, as for example alcohols such as geraniol,nerol, citronellol, linalol, tetrahydrogeraniol, betaphenylethylalcohol, methyl phenyl carbinol, dimethyl benzyl carbinol, menthol orcedrol; acetates and other esters derived form such alcohols-aldehydessuch as citral, citronellal, hydroxycitronellal, lauric aldehyde,undecylenic aldehyde, cinnamaldehyde, amyl cinnamic aldehyde, vanillinor heliotropin; acetals derived from such aldehydes; ketones such asmethyl hexyl ketone, the ionones and methylionones; phenolic compoundssuch as eugenol and isoeugenol; synthetic musks such as musk xylene,musk ketone and ethylene brassylate.

In one embodiment relating to releasing material having a relativelyfine particle size, many small interconnecting channels throughout thepolymer should be produced, as opposed to a few large interconnectingchannels that will expose less surface area within the polymer. In oneembodiment, dimer agents such as polypropylene maleic anhydride, or anyplasticizer, may be optionally added to the mixture reducing viscositiesand increasing the mixing compatibility of the polymer and hydrophilicagent.

In yet another embodiment, releasing materials are selected having apolarity that causes an affinity between the releasing agent and thehydrophilic agent. For this reason, during the separating process whenthe interconnecting channels are formed throughout the polymer, it isbelieved that the releasing material will migrate toward the hydrophilicagent domains to which it is attracted. In this manner, it is theorizedthat the hydrophilic agent is permitted to act as a bridge betweenmoisture located exteriorly to the polymer structure and the releasingmaterial that is located within the polymer. This is particularly truewith respect to a releasing material that is bound within thehydrophilic agent filled passages. In a further embodiment, polarplasticizers such as glycerin may be further added to the mixture whichenhance the dispersion or mixing of the releasing material into thehydrophilic agent.

It is believed that the higher the releasing material concentration inthe mixture, the greater the absorption capacity will be of the finalcomposition. However, the higher releasing material concentration shouldcause the body to be more brittle and the mixture to be more difficultto either thermally form, extrude or injection mold. In one embodiment,the releasing material loading level can range from 10% to 20%, 20% to40% and 40% to 60% by weight with respect to the polymer.

In one embodiment, the water-insoluble polymer of the present inventionmay be any thermoplastic material. Examples of suitable thermoplasticmaterials include polyolefins such as polypropylene and polyethylene,polyisophrene, polybutadiene, polybutene, polysiloyane, polycarbonates,polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylatecopolymer, poly(vinyl chloride), polystyrene, polyesters,polyanhydrides, polyacrylonitrile, polysulfones, polyacrylic ester,acrylic, polyurethane and polyacetal, copolymers or mixtures thereof.

In yet another embodiment, the components are first dry mixed in a mixersuch as a Henschel, and then fed to a compounder. A Leistritz twin screwextruder, for example, or a Werner Pfleider mixer can be used to achievea good melt mix at about 140° C. to about 170° F. The melt can then beeither extruded to form, for example, a film or converted into pelletsusing dry air cooling on a vibrating conveyer. The formed pellets,containing channels, can, for example, then be either injection moldedinto beads, sieves, or co-injected with polypropylene as the insidelayer of a container.

In yet a further another embodiment, because the composition of thepresent invention may typically be more brittle than the polymer withoutthe releasing material, the package may be molded so that an interiorportion of the package is the composition of the present invention whilethe exterior portions are formed from pure polymer or the composition ofthe present invention with a lower releasing material loading level. Forexample, a package having an interior portion composed of thecomposition of the present invention and an exterior portion composed ofpure polymer typically will not only be more durable and less brittle,but it will also act as a barrier that resists the transmission ofmoisture from the exterior into the interior of the package. In thismanner, the capacity of the releasing material is potentiated byexposing it exclusively to the interior of the package from which it isdesired that the material will be released.

The composition of the present invention has numerous applications. Oneapplication is the construction of rigid containers that are suitablefor containing relatively small volumes of product such as food stuffsand medicines. In many cases, these types of products must be shippedand stored in controlled environments (e.g. reduced moisture and/oroxygen). In another embodiment, the composition of the present inventionmay be formed into an insert for inclusion within the interior of thecontainer. An example of one form of an insert is a plug of any suitableshape. While the plug would serve its purpose by being merely depositedwithin the container, it may also be fixed to an interior location sothat it does move about within the interior space. In a furtherembodiment, it is anticipated that a plug formed into a disc may beshaped and sized to be pressed fit into the bottom of a polymer formedcontainer.

In another embodiment, a liner may be formed from the composition of thepresent invention that has an exterior surface substantially conformingto an interior surface of the container body. Like the disc, the linermay be sized so that it may be press-fit into position within thepolymer body where it is held sufficiently snugly to prevent itsunintended disengagement therefrom. Alternatively, in a furtherembodiment, either the plug or liner may be initially constructed andallowed to harden, and then the container body subsequently constructedthereabout so that the greater shrinkage characteristics of the polymerbody not containing the releasing material tightly shrink-fits thecontainer body about the plug or liner so that neither becomes easilydisengaged from the other. In still a further embodiment, the inserttaking the form of either a plug or a liner may be substantiallysimultaneously comolded with the polymer container body so that each isintegrally joined with the other. In the event of a co-molding process,the viscosities of the desiccant laden insert and the polymer containerbody should typically be approximately equal to facilitate the properand desired location of the two phases of liquid or molten material thatare molded together.

In yet another embodiment, composition of the present invention may beused to form sheeting that is joined with another sheet. In at least oneembodiment, the sheets are effectively laminated one to the other sothat an exterior layer may be established adjacent to the composition ofthe present invention which is substantially air and moistureimpermeable. The laminate sheet may then be used to wrap an item whichis to be stored in a controlled environment. One means by which thejoinder process may be accomplished is through a thermal extrusionprocedure.

In each of the embodiments of the present invention described herein,advantages and enhancements over the prior art methods and structuresstem from the discovery of the ability to create interconnectingchannels throughout the composition of the present invention so that arigid body may be constructed from the composition of the presentinvention while also exposing the releasing material to the environment.Furthermore, the discovery of employing a hydrophilic agent that alsoacts as a transmission rate bridge between the exterior of the polymerbody and the interiorly located releasing material greatly enhances thestructures' ability to quickly remove the desired property locatedexteriorly to the entrained structure, while at the same time takingadvantage of a greater portion of the material's capacities.

One embodiment of the present invention includes a process for producingthe composition of the present invention. In one embodiment, the processcomprises blending a water-insoluble polymer and a hydrophilic agent.Either prior to blending the hydrophilic agent or after blending thehydrophilic agent, the releasing material is blended into the polymer sothat the additive is uniformly distributed within the polymer and thehydrophilic agent is distributed within the polymer. Subsequently, afterthe composition is solidified, the result is that the hydrophilic agentforms interconnecting channels in the composition through which thedesired property is transmitted through the polymer to the releasingmaterial within the composition. In another embodiment, the hydrophilicagent and releasing material are all thoroughly mixed in dry powderform, and then the polymer blend is melted and formed into a desiredshape by molding. Interconnecting channels are formed in the compositionthrough which the desired property is transmitted through the polymer tothe releasing material within the composition.

In an alternative embodiment of the present invention, the monolithiccomposition comprising a water-insoluble polymer, a hydrophilic agentand a releasing material may be made by first producing a two phasesystem comprising the water-insoluble polymer and the hydrophilic agent,then immersing the two phase system in a solution containing thereleasing material. As a result, the releasing material is taken up bythe composition and results in a monolithic composition consisting of atleast three phases comprising the water-soluble polymer, the hydrophilicagent and the releasing material. It is to be understood that, forpurposes of the present invention, immersing includes soaking, coatingor other methods that result in an uptake of the releasing material bythe composition.

One specific example consists of (1) mixing the water-insoluble polymerand the hydrophilic agent to produce a uniform blend; (2) heating theblend of step (1) to a temperature above the melting point of thehydrophilic agent; (3) cooling the blend of step (2) to form the desiredshaped article; (4) immersing the shaped article of step (3) in asolution containing the releasing material; (5) drying under suitableconditions that would not detrimentally affect the materials; and (6)forming a shaped article comprising a monolithic composition comprisingthe water-insoluble polymer; the hydrophilic agent and the releasingmaterial.

This alternative embodiment may be well-suited for materials that areheat-sensitive and thus, that may not be capable of withstanding thetemperatures required to melt the hydrophilic agent during processing.An example of such high temperatures are the temperatures incurredduring the extrusion step. Consequently, the releasing material may beadded downstream from the extrusion and thus, are not subject to highertemperatures, which may detrimentally effect the material. A furtherexample of this alternative embodiment relates to producing the solutionfor the releasing material. In one embodiment, an aqueous solution ofthe releasing material is produced.

In one embodiment, the composition of the present invention is used toform a plug for inclusion within a package constructed of a barriersubstance. In another, the composition of the present invention is usedto form a liner for inclusion within a container constructed from abarrier substance. In still another embodiment, the composition of thepresent invention is used to form an absorption sheet. The absorptionsheet may optionally be combined with a barrier sheet constructed of abarrier substance for use as a packaging wrap. In another embodiment,the composition of the present invention is used to form an absorbinginsert for a container.

Referring to FIG. 1 of the accompanying drawings of an embodiment of thepresent invention, an insert constructed from the composition of thepresent invention 20 is illustrated. For purposes of this disclosure ofthe present invention, the words “entrain” and “contain” have been usedinterchangeably when referring to the inclusion of a desiccating agent30 in a polymer 25 matrix. The insert is in the form of a plug 55 thatmay be deposited into a container body 60 (FIG. 5) thereby establishinga container 61 (FIG. 5). Referring to FIG. 2, a cross-sectional view isshown of the plug 55 that has been constructed from a polymer mixturecomprising the water-insoluble polymer 25 that has been uniformlyblended with the releasing material 30 and the hydrophilic agent 35. Inthe illustration of FIG. 2, the composition of the present invention hasbeen solidified so that interconnecting channels 45 have formedthroughout the composition to establish passages throughout thesolidified plug 55. As may be appreciated in both FIGS. 1 and 2, thepassages terminate in channel openings 48 at an exterior surface of theplug 55.

FIG. 3 illustrates the embodiment of a plug 55 similar in constructionand makeup to the plug 55 of FIG. 2, where interconnecting channels arevery fine. This can result from the use of polyglycols as thehydrophilic agent, or the use of a dimer agent (i.e., a plasticizer)together with a hydrophilic agent. The dimer agent 50 may enhance thecompatibility between the polymer 25 and the hydrophilic agent 35. Thisenhanced compatibility is facilitated by a lowered viscosity of theblend which should promote a more thorough blending of the two compounds25,35 which resists combination into a uniform solution. Uponsolidification of the composition of the present invention that has hada dimer agent added thereto, the interconnecting channels which areformed therethrough have a greater dispersion and a smaller porositythereby establishing a greater density of interconnecting channelsthroughout the plug 55. In one embodiment, this same effect occursreadily when a polyglycol is used as the hydrophilic agent due to thegeneral comparability of polyglycols with hydrophobic thermoplasticssuch as polyolefins. The interconnecting channels are created to providepathways for controlled transmission of the desired property from theexterior of the solidified plug 55 to interior locations where theentrained releasing material 30 is bound.

It is believed that these interconnecting channels are required becauseof the hydrophobic characteristics of the polymer 25 that resistpermeability therethrough and therefore acts as a barrier. For thisreason, the polymer 25 itself is referred to as a barrier substancewithin which a releasing material 30 may be entrained. To expose thereleasing material 30 entrained within the interior of the polymer 25,however, the interconnecting channels 45 are provided. Without theseinterconnecting channels 45, it is believed that relatively smallquantities of the releasing material would be released by the entrainedreleasing material 30. It is further believed that these small amountsderive from the limited number of releasing material particles 30 thatwould be exposed at the exterior surface of the formed body and the verysmall amounts of the releasing agent that would be able to pass throughthe substantially impermeable polymer 25. Because of thesecharacteristics, the water-insoluble polymer 25 is referred to as abarrier even though it may not be completely impermeable.

FIG. 3 illustrates an embodiment of the present invention of a plug 55which has been deposited into a container body 60 thereby establishing areleasing container 61. The container body 60 has an interior surface 65and is constructed substantially from the composition of the presentinvention. In this manner, the transmission property is resisted frombeing transmitted across a wall of the container 60 when the container60 is closed. As may be seen in FIG. 3, the plug 55 has been press fitinto a bottom location of the container 60. It is contemplated that theplug 55 may be merely deposited in the container 60 for loosecontainment therein, but it is preferable coupled to the body of thecontainer 60 in a manner that fixes the plug 55 to the container 60. Thecouple between the plug 55 and the container body 60 is intended toprevent the dislocation and relative movement of the plug 55 thereabout.This connection may be accomplished by a snug press fit between the plug55 and the interior surface 65 of the body 60, or it may be mechanicallyconnected in such manners as adhesives, prongs, lips or ridges thatextend about the plug 55 to hold the plug 55 in place. In yet anotherembodiment, it is contemplated that the container body 60 may be moldedabout the plug 55 so that during the curing process of the containerbody 60 the body 60 shrinks about the plug 55 thereby causing ashrink-fit to be established between the two components. This type ofcouplement may also be accomplished in a comolding process or sequentialmolding process with the same results achieved because the plug 55 willhave less shrinkage than the polymer 25 comprised container body 60.

FIG. 4 illustrates a releasing container 61 having the composition ofthe present invention formed of a plug 55 located at a bottom locationof the container 60 similar to the configuration illustrated in FIG. 3,but the plug 55 and container body 60 are comolded so that a unifiedbody 61 is formed with a less distinct interface between the plug 55 andbody 60 components.

FIGS. 5 and 6 illustrate concepts similar to those of FIGS. 3 and 4,however the proportions of the plug 55 have been extended so that aliner 70 is formed which covers a greater portion of the interiorsurface 65 of the container 61. The liner 70 is not localized in thebottom portion of the container body 60, but has walls which extendupwardly and cover portions of the walls of the container 61. Like theplug 55, the liner 70 may be separately molded and subsequently combinedwith the container body 60 or it may be comolded therewith into theunified body illustrated in FIG. 6.

FIGS. 7 and 8 illustrate an embodiment of the invention in which areleasing material formed of a sheet of the present invention 75 iscreated for combination with a barrier sheet 80. The characteristics ofthe sheets are similar to those described with respect to the plug 55and liner 70 and container body 60. That is, FIG. 7 illustrates anembodiment in which the two sheets 75, 80 are separately molded, andlater combined to form a packaging wrap having releasing materialcharacteristics at an interior surface and resistant characteristics atan exterior surface. FIG. 8 illustrates a comolded process wherein aninterface between the sheet 75 and the barrier sheet 80 is less distinctthan in the embodiment of FIG. 7. This product can be produced by athermal, forming process. In such a process, the polymer layer is meltedand partially formed into a sheet with the releasing material 30 beingdeposited on top of that layer just prior to being pressed or extrudedthrough a slit like opening in the thermal forming machine. It iscontemplated that the separate sheets 75, 80 of FIG. 7 may be joinedtogether with an adhesive or other suitable means to form a laminatefrom the plurality of sheets 75, 80. Alternatively, the sheeting 75, 80may be manufactured from a thermal extrusion process whereby both sheets75, 80 are manufactured at the same time and effectively comoldedtogether to form the embodiment illustrated in FIG. 8.

In a further embodiment of the present invention, a plug 55 is formedfrom the mixture for inclusion within a container 60 that is constructedfrom a barrier substance. In one embodiment, the plug 55 is depositedinto a container 60 that is constructed from a barrier substance. Inthis manner, a container 61 is created. The plug 55 may be coupled to aninterior surface of the container body 60 so that the plug 55 is fixedrelative to the container 60.

Alternatively, a container 60 constructed from a barrier substance maybe molded about the plug 55 so that at least a portion of the plug 55 isexposed to an interior of the container 60. A desiccating plug 55 madeaccording to the present invention may also be co-molded with acontainer 60 that is constructed from a barrier substance so that atleast a portion of the plug 55 is exposed to an interior of thecontainer 60.

In another embodiment, a liner 70 may be formed from the mixture 40 andthen be included within a container 60 constructed from a barriersubstance. The liner 70 typically, but not necessarily, has an exteriorsurface configured for mating engagement with an interior surface 65 ofthe container 60.

The liner 70 may be pressed into mating engagement with the container 60so that a container 61 is created wherein at least a majority of theinterior surface 65 of the container is covered by the liner 70.

The liner 70 may be formed from the mixture 40 and then a container 60constructed from a barrier substance may be molded about the liner 70 sothat at least a portion of the liner 70 is exposed to an interior of thecontainer 60 and a majority of an interior surface 65 of the container60 is covered by the liner 70.

Alternatively, the liner 70 and container body 60 may be comoldedtogether into a unified body.

The absorbing sheet 75 is combined with a barrier sheet 80 that isconstructed of a barrier substance for use as a packaging wrap.

The sheets 75, 80 may be laminated by thermal extrusion.

A dimer agent may optionally be added to the mixture to increase themixing compatibility of the polymer 25 and the channeling agent 35thereby increasing the dispersion of the passages within the solidifiedmixture.

In still another embodiment of the present invention, a method formaking a releasing material formed in the shape of container 61 isprovided. The method includes forming a container 60 from substantiallyair and moisture impermeable material so that an air and moisturebarrier is created between an interior and exterior of the container. Aninsert is formed from composition of the present invention. The inserthas an exterior surface that is configured for mating engagement with atleast a portion of an interior surface 65 of the container 60. Theinsert is installed into the interior of the container 60 so that atleast a portion of the exterior surface of the insert abuttingly engagesthe interior surface 65 of the container 60. The engagement fixes theinsert relative to the container 60 and resists disengagement of theinsert from the container 60. The insert is exposed to the interior ofthe container 60 for releasing the desired property. The insert ispressed into the interior of the container 60 with sufficient force thatthe insert fits tightly within the container 60 thereby resistingdisengagement therefrom. The insert is sized and shaped so that theinsert fits snugly into a receiving location within the interior of thecontainer for retention at the receiving location.

In another embodiment, the insert is sized and shaped into a plug 55that fits snugly into a receiving location at a bottom portion of theinterior of the container 60 for retention at the receiving location.

In a further embodiment, the insert is configured into a liner 70 havingan exterior surface that conforms to the interior surface 65 of thecontainer 60 so that a majority of the liner's 70 exterior surface is inabutting engagement with the container's 60 interior surface 65. Thecontainer 60 and the liner 70 are similarly configured so that theinterior 65 of the container 60 and the exterior of the liner 70 fitsnugly together so that disengagement of the liner 70 from the container60 is resisted.

In another example, the container 60 may be molded from a plastic thatis substantially impermeable and therefore resists the transmission ofthe releasing material across the boundary of the container 60 betweenits exterior and its interior. Also, the liner 70 may be molded from thecomposition of the present invention.

In yet another embodiment, a method for making a releasing materialformed in the shape of container 61 is provided. A container is formedfrom substantially air and moisture impermeable material so that abarrier is established between an interior and exterior of the container60. A substantially solid tablet or plug 55 is formed from thecomposition of the present invention 20, the tablet 55 being suitablysized to fit within the interior of the container 60. The tablet 55 isthen deposited into the interior of the container 60 therebyestablishing a means for releasing the desired material from theinterior of the container 60 when the container 60 is closed about thetablet 55.

In another embodiment of the present invention, a method for making areleasing material in the shape of a package is provided. An outer skin,sheet, or layer 80 is formed from a substantially air and moistureimpermeable sheet of material so that a barrier is created betweenopposite sides of the skin. An inner skin, sheet, or layer 75 is formedfrom the composition of the present invention 20 at one side of theouter skin 80. A package is formed about a product or item by sealingthe product or item within the outer impermeable skin 80 and with theinner releasing material skin 75 located adjacent to the product. Areleasing material laminate may be formed by suction vacuum molding theouter skin 80 and the inner skin 75 together to form the package.

In one embodiment of the present invention, a releasing material in theform of an enclosure 61 is provided. The enclosure includes a container60 formed from substantially moisture and air impermeable material sothat a barrier is created between an interior and exterior of thecontainer 60. A liner 70 is formed from the composition of the presentinvention 20 so that the liner 70 has an exterior surface configured formating engagement with at least a portion of an interior surface 65 ofthe container 60. The liner 70 is inserted into the interior of thecontainer 60 so that at least a portion of the exterior surface of theliner abuttingly engages the interior surface 65 of the container 60.The engagement fixes the liner 70 relative to the container 60 andresists disengagement of the liner 70 from the container 60.

In another embodiment of the present invention, a releasing material inthe form of an insert for a closable container 60 includes an insertmade from the composition of the present invention is configured forinstallation into a closable container 60. The insert 25 is constructedfrom the composition of the present invention. The insert 25 haspassages extending from its exterior surface into its interior.

The present invention will be illustrated in greater detail by thefollowing specific examples. It is understood that these examples aregiven by way of illustration and are not meant to limit the disclosureor claims. For example, although the following examples were tested at10% Rh and 20% Rh at 72° F., the composition of the present invention isalso suited for other conditions. Moreover, these examples are meant tofurther demonstrate that the present invention has interconnectingchannels and that the hydrophilic agents reside in the interconnectingchannels. All percentages in the examples or elsewhere in thespecification arc by weight unless otherwise specified.

EXAMPLE 1

The purpose of the following example is to demonstrate that thecomposition of the present invention has interconnecting channels bysubjecting the following materials to a swelling and weight lossanalysis. In addition, the following example demonstrates that thecomposition of the present invention is able to release a substance(e.g., poly(ethylene glycol)).

A. Preparation of Samples

Film #1: A blend of about 93% (w/w) of polypropylene (Exxon Chemicals,tradename Escorene® polypropylene 3505G) and about 7% (w/w) ofpoly(ethylene glycol) (Dow Chemical, tradename E-4500) was sufficientlymixed to produce a uniform blend. The blend was then fed through aLeistritz twin screw extruder at temperatures in the sixteen zonesranging from about 145° C. to about 165° C., at a feed rate of about 40lbs/hr, at a screw speed of about 460 rpm and a six inch die. Theextruded composition was then fed through a three roll hot press attemperatures ranging from about 85° C. to about 92° C. to produce a filmof about 4 mil.

Film #2: A blend of about 68% (w/w) of polypropylene (Exxon Chemicals,tradename Escorene® polypropylene 3505G) and about 3505G), about 12%(w/w) of poly(ethylene glycol) (Dow Chemical, tradename E-4500) andabout 20% (w/w) of a desiccant of molecular sieve (Elf Atochem,tradename Siliporite® molecular sieve, 4 Angstrom) was sufficientlymixed to produce a uniform blend. The blend was then fed through aLeistritz twin screw extruder at temperatures in the sixteen zonesranging from about 145° C. to about 165° C., at a feed rate of about 40lbs/hr at a screw speed of about 460 rpm and a six inch die. Theextruded composition was then fed through a three roll hot press attemperatures ranging from about 85 to about 92° C. to produce a film ofabout 4 mil.

Film #3: A blend of about 34.88% (w/w) of polypropylene (Exxon Chemical,tradename Escorene® polypropylene 3505G), about 11.96% (w/w) ofpoly(ethylene glycol) (Dow Chemical, tradename E-4500), about 52.82%(w/w) of a desiccant of molecular sieve (Elf Atochem, tradenameSiliporite® molecular sieve, 4 Angstrom) and about 0.34% (w/w) of a greycolorant was sufficiently mixed to produce a uniform blend. The blendwas then fed through a Leistritz twin screw extruder at temperatures inthe sixteen zones ranging from about 145° C. to about 165° C., at a feedrate of about 50 lbs/hr at a screw speed of about 460 rpm and a six inchdie. The extruded composition was then fed through a three roll hotpress at temperatures ranging from about 85 to about 92° C. to produce afilm of about 4 mil.

B. Swelling and Weight Loss Analysis

Circular disks (OD 1.1 cm) were cut from each of the three samples.Initial dry weights of each sample was recorded. Samples weresubsequently incubated in 2.0 ml distilled water and left shaking atroom temperature. Periodically at 1, 2, 3, and 34 days, the disks wereremoved, the surface blotted dry and the sample weighed, to determinethe extent of swelling. At each timepoint, the distilled water wasreplaced to provide for sink conditions. At the end of the study, thesamples were lyophilized to remove the water and the sample weighed todetermine mass loss. FIG. 9 is a graph of the result of the analysis.Percent swelling is defined as the wet weight at a time point (t),divided by initial dry weight (zero) and multiplied by 100. ‘Dry’indicates the final lyophilized sample weight following the 34 dayincubation.

FIG. 9 shows film #1 did not swell or lose weight over the course of 34days. Thus, it is believed that this result shows that the poly(ethyleneglycol) (i.e., hydrophilic agent) was completely entrapped in thepolypropylene (i.e., water-insoluble polymer). Film #2 gainedapproximately 3% of its initial weight by swelling and lostapproximately 9% of its initial weight at the end of the 34 days ofincubation. Film #3 gained approximately 6% of its initial weight andlost approximately 8% of its initial weight at the end of the 34 dayincubation period. These results demonstrate that interconnectingchannels from the exterior through the interior exist in the compositionof the present invention because water penetrated films #2 and #3 and asubstantial portion of the water soluble component (e.g., poly(ethyleneglycol)) of films #2 and #3 was extracted from the polymer.

EXAMPLE 2

The purpose of the following example is to demonstrate that thecomposition of the present invention has two separate phases consistingof a water-insoluble polymer and a hydrophilic agent.

A. Preparation of Samples

Film #4: 100% polypropylene (Exxon Chemicals, tradename Escorene®polypropylene 3505G) was fed through a Leistritz twin screw extruder attemperatures in the sixteen zones ranging from about 145° C. to about165° C., at a feed rate of about 40 lbs/hr, at a screw speed of about460 rpm and a six inch die. The extruded composition was then fedthrough a three roll hot press at temperatures ranging from about 85° C.to about 92° C. to produce a film of about 4 mil.

Film #5: A blend of about 88% (w/w) of polypropylene (Exxon Chemicalstradename Escorene® polypropylene 3505G), about 12% (w/w) ofpoly(ethylene glycol) (Dow Chemical, tradename E-4500) was sufficientlymixed to produce a uniform blend. The blend was then fed through aLeistritz twin screw extruder at temperatures in the sixteen zonesranging from about 145° C. to about 165° C., at a feed rate of about 40lbs/hr, at a screw speed of about 460 rpm and a six inch die. Theextruded composition was then fed through a three roll hot press attemperatures ranging from about 85° C. to about 92° C. to produce a filmof about 4 mil.

Film #7: A blend of about 68% (w/w) of polypropylene (Exxon Chemicals,tradename Escorene® polypropylene 3505G), about 12% (w/w) ofpoly(ethylene glycol) (Dow Chemical, tradename E-4500) and about 20%(w/w) of a desiccant of molecular sieve (Elf Atochem, tradenameSiliporite® molecular sieve, 4 Angstrom) was sufficiently mixed toproduce a uniform blend. The blend was then fed through a Leistritz twinscrew extruder at temperatures in the sixteen zones ranging from about145° C. to about 165° C., at a feed rate of about 12 lbs/hr, at a screwspeed of about 460 rpm and a six inch die. The extruded composition wasthen fed through a three roll hot press at temperatures of about 105° C.to produce a film of about 4 mil.

B. Thermal Analysis Using Differential Scanning Calorimetry (“DSC”)

The processed film samples were analyzed using a Perkin Elmer DSC7equipped with a TAC 7DX thermal controller. Data were analyzed usingPerkin Elmer Pyris software (version 2.01). Samples were heated from −50to 250° C. at a rate of 10 or 15° C./min, then cooled at the same rateand then heated once again to 250° C. at the same rate. The followingtable is the date collected from the DSC. The melting point data isgiven as the melting point peak (° C.) and enthalpy (ΔH, joules/gm) forthe first heating ramp (1°) and the second heating ramp (20°). Thecolumn referring to FIGS. 10 through 18 is the graphical output from theDSC that corresponds to the date from the table. Since the samples areonly heated to 250° C., the molecular sieve in film samples #2, #3 and#7 was not melted and thus, no melting point date was recorded.

PEG PEG PP PP Sample FIG. # Peak° C. ΔH J/g Peak° C. ΔH J/g 100% FIG 101°63.808 190.362 none None poly(ethylene glycol) Film #4 FIG 11 1° noneNone 162.700 78.462 2° none None 157.200 96.123 Film #5 FIG 12 1° 57.70022.253 161.700 80.524 2° 58.033 20.361 157.366 79.721 Film #6 FIG 13 1°none None 159.366 42.385 2° none None 160.033 42.876 Film #7 FIG 14 1°56.366 19.460 162.200 70.073 2° 57.200 17.094 156.866 58.038 Film #2 FIG15 1° 58.554 20.845 163.062 60.577 [pre-incubation] 2° 58.779 16.037157.783 53.706 Film #2 FIG 16 1° 55.804 0.379 163.062 86.215[post-incubation] 2° 57.529 0.464 158.533 67.949 Film #3 FIG 17 1°59.308 18.849 162.562 40.291 [pre-incubation] 2° 56.529 10.122 158.28324.980 Film #3 FIG 18 1° 55.554 0.138 160.562 46.931 [post-incubation]2° none None 156.033 26.081

The 100% poly(ethylene glycol) sample, exhibits a single melting pointat 63° C. while film #4 100% polypropylene has a melting point at 157°C. Film #5 displayed both peaks at 58° C. (poly(ethylene glycol)) and157° C. (polypropylene), which indicates that the two polymers werephase separated. If the polymers were not phase separated but mixed,then the peaks would not be at the melt temperatures of the purepolymers, but shifted. Film #6 shows only the distinct polypropylenepeak at 160° C. The molecular sieves do not melt in this temperaturerange or affect the melting temperature of pure polypropylene. Film #7again shows two distinct peaks: one for poly(ethylene glycol) at 57° C.and one for polypropylene at 157° C. indicating that in the threecomponent mixture, all are phase separated.

Film samples #2 and 3 were part of the swelling and weight loss analysispresented in Example 1. Once again two distinct peaks were evident: onefor poly(ethylene glycol) at 59° C. and one for polypropylene at 158° C.indicating that in the three component mixture, all components werephase separated. However when the polymer film was incubated in waterfor 34 days at room temperature (File #2: post-incubation) and tested byDSC, the positions of the peaks remained the same indicating thecomponents were still phase-separated. However the area of thepoly(ethylene glycol) peak (indicated by delta H, enthalpy) was greatlyreduced. This result indicated that poly(ethylene glycol) had beenextracted by the prolonged water incubation. Also, the result providedfurther confirmation for the weight loss data presented in Example 1 anddemonstrated that the poly(ethylene glycol) component was mostlyextracted by means of interconnecting channels in the bulk polypropylenematrix.

Film sample #3 showed the same effect as Film sample #2. Thepolypropylene delta H peak was not detectable (Film #3:post-incubation), demonstrating nearly complete extraction ofpoly(ethylene glycol) during water incubation. This confirmed the weightloss result of Example 1 in which the same film lost approximately 8% ofit's initial weight. The poly(ethylene glycol) composition of the samplewas approximately 12% (w/w).

In addition, the glass transition (T_(g)) analysis from the DSC data ofthe samples of the present invention also demonstrate that thewater-insoluble polymer and the material exist in separate phases. Purepolypropylene exhibits a T_(g) of about −6° C. while pure poly(ethyleneglycol) exhibits a T_(g) at about −30° C. DSC data from film #5 exhibittwo distinct T_(g)'s, which correspond to the respective polymers (6° C.for polypropylene and −30° C. for poly(ethylene glycol) and thus,indicates, further that the two components are phase separated.

EXAMPLE 3

The purpose of the following example is to demonstrate that thecomposition of the present invention has interconnection channels andhas the water absorbing material intermixed within the hydrophilicagent.

A. Scanning Electron Microscopy (“SEM”) Method

The structural properties of the films was imaged using a Hitachi S-2700microscope operating at 8 kV accelerating voltage to minimizeirradiation damage. Each film sample was visualized in threeperspectives: 1) the film surface; 2) the fractured film cross-section(0°) and 3) the fractured film cross-section at a 90° angle with respectto orientation #2 (90°). Pre-incubation film samples were directlysputter coated with a 5-10 nm layer of gold-palladium with a PolaronInstruments Sputter Coater E5100. Post-incubation samples were incubatedat room temperature for 24 hrs in 10 ml of 70% ethanol (w/v) withagitation. The ethanol was discarded and the samples were air-driedovernight. Samples were then frozen and lyophilized overnight to removeany residual moisture and then sputter coated.

B. Morphology of Film Samples

FIGS. 19a-c are scanning electron photomicrographs of film sample#4—100% polypropylene. FIGS. 19a-c illustrate that a water-insolublepolymer is typically a dense, homogenous morphology with substantiallyno porosity. The outer surface is shown in FIG. 19a FIG. 19a shows anouter surface that is dense and displaying substantially no porosity.The cross-sectional view is shown in FIG. 19b at a magnification of 200times. FIG. 19b shows plate-like domains of polymer that were revealedduring brittle facture of the film. Another cross-sectional view isshown in FIG. 19c at a magnification of 1000 times. FIG. 19C shows adense, fibrillar morphology.

FIGS. 20a-c are scanning electron photomicrographs of film samples#5—about 88% polypropylene and 12% poly(ethylene glycol). FIGS. 20a-cillustrate that a two phase system consisting essentially of awater-insoluble polymer and hydrophilic agent has a heterogeneousmorphology with dense fibrallar matrix interspersed with domains oflamellar structures, which is the poly(ethylene glycol). FIGS. 20a-cfurther show voids between lamellar fibrillar and fibrillar structuresthat are channels and are oriented in the same direction. The outersurface is shown in FIG. 20a at a magnification of 1000 times. FIG. 20ashows an outer surface that is dense and displaying substantially noporosity. The cross-sectional view is shown in FIG. 20b at amagnification of 2,500 times. FIG. 20b shows fibrillar domains ofpolymer coated with lamellar strands of poly(ethylene glycol). FIG. 20cis a cross-sectional view of film sample #5 fractured a perpendicularangle and at a magnification of 1,500 times. FIG. 20c shows thefibrillar polypropylene matrix interspersed with solid, amorphouscylinder of poly(ethylene glycol).

FIGS. 21a-c are scanning electron photomicrographs of film sample#6—about 50% polypropylene and 50% molecular sieve. FIGS. 21a-cillustrate a typically homogeneous dense matrix and discrete molecularsieves can only occasionally be seen and are deeply embedded in thepolymer despite the high loading of molecular sieves. FIG. 21a shows theouter surface at a magnification of 1,000 times that is covered withlong channels measuring 5-30 microns. The outline of the molecularsieves (1-10 microns) can be seen embedded beneath the surface of thepolymer. The cross-sectional view is shown in FIG. 21b at amagnification of 200 times. FIG. 21b shows plate-like domains of polymerand a grainy appearance due to the high loading of molecular sieves.FIG. 21c is a cross-sectional view at a magnification 1,500 times andshows a dense morphology, substantially no porosity and many smallparticles embedded in the polymer.

FIGS. 22a-d are scanning electron photomicrographs of film samples#3—about 52% molecular sieve, about 34% polypropylene and about 12%poly(ethylene glycol). FIGS. 22a-d show a three phase system with ahighly porous morphology. FIG. 22a shows the outer surface at amagnification of 500 times that is covered with long channels, measuring5-30 microns, and that is filled with numerous discrete molecular sieveparticles. A cross-sectional view is shown in FIG. 22b at amagnification of 350 times. FIG. 22b shows a very porous morphology withlong channels running in the fracture orientation. FIG. 22c is across-sectional view in the perpendicular orientation at a magnificationof 350 times and appears to show holes. FIG. 22 is at highermagnifications—1,500 times. FIG. 22d shows channels containing discretemolecular sieves as well as agglomerates of many sieves embedded in thepoly(ethylene glycol). Consequently, based on FIG. 22b, it is believedthat the holes seen in FIGS. 22b and 22 c are locations where themolecular sieve fell out during fracture preparation for SEM.

In conclusion, Examples 1, 2 and 3 further confirm the theory for theformation of interconnecting channels. Since, in one embodiment, theprocess begins at a temperature at which the hydrophilic agent is inmolten form while the water-insoluble polymer is in solid form, it isbelieved that the third component (e.g. molecular sieve) is interactingwith the liquid hydrophilic agent. Consequently, it is believed that, atthis point, the interconnecting channels are formed because thehydrophilic agent flows easily and fills the gaps between the solidwater-insoluble polymer and the molecular sieve components. As theprocess continues and the temperature increases, the water-insolublepolymer melts and thus, the composition becomes more uniform.

EXAMPLE 4

The purpose of the following example is to demonstrate the waterabsorption properties of the compositions of the present invention.Samples of film with similar processing conditions as film #1 were madehaving about 50% (w/w) of molecular sieve [4 Angstrom], about 12% (w/w)poly(ethylene glycol) and about 38% (w/w) polypropylene and wereevaluated for moisture adsorption of its total weight by using thefollowing test method (a) one environmental chamber was preset for 72°F. and 10% relative humidity (“Rh”) and another chamber was preset for72° F. and 20% Rh; (b) the dish was weighed and the weight recorded; (c)the scale was then tared to remove the weight of the dish from thebalance; (d) the film was then added to the weighed dish; (e) thematerial was then weighed and the weight recorded; (f) the weigh dishwith the sample was placed in the environmental chamber; (g) the samplewas left in the chamber for the desired time; (h) after the desired timewas reached, the dish with the sample was removed, re-weighed and theweight recorded; and (i) the precent moisture gained per gram ofmolecular sieve was calculated by (total weight gain of sample)/(weightof molecular sieve in sample)×100. The results are presented in FIGS.23a [10% RH] and 23 b [20% Rh] The maximum theorectical precent moisturegained per weight of a 4 Angstrom molecular sieve is about 24 to 25%.FIGS. 23a and 23 b demonstrate that the high transmission rate (e.g.,moisture absorption rate) of the present invention.

Monolithic compositions and their constituent compounds have beendescribed herein. As previously stated, detailed embodiments of thepresent invention are disclosed herein; however, it is to be understoodthat the disclosed embodiments are merely exemplary of the inventionthat may be embodied in various forms. It will be appreciated that manymodifications and other variations that will be appreciated by thoseskilled in the art are within the intended scope of this invention asclaimed below without departing from the teachings, spirit and intendedscope of the invention.

What is claimed is:
 1. An article of manufacture comprising a monolithiccomposition formed by combining at least the following components: apolymer having a solubility in water below about 0.1% at 25° C. andatmospheric pressure; a hydrophilic agent is at least about 10% byweight of the polymer and is selected from the group consisting ofpolyglycols poly(ethylene glycol), poly(propylene glycol), EVOH,pentaerithritol, PVOH, polyvinvlpyrollidine, vinylpyrollidone orpoly(N-methyl pyrollidone), and saccharide based compounds, glucose,fructose and their alcohols, mannitol, dextrin, and hydrolized starchand mixtures thereof; and a releasing agent selected from the groupconsisting of pesticides, nematocides, fungicides and rodenticides;wherein the composition comprises at least three phases and hasinterconnecting channels with the releasing agent in or adjacent tothese channels.
 2. The article of manufacture of claim 1 wherein thepolymer is a thermoplastic.
 3. The article of manufacture of claim 1,wherein the hydrophilic agent is a polyglycol.
 4. An article ofmanufacture comprising a monolithic composition formed by combining atleast the following components: a polymer having a solubility in waterbelow about 0.1% at 25° C. and atmospheric pressure; a hydrophilic agentis at least about 10% by weight of the polymer and is selected from thegroup consisting of polyglycols, poly(ethylene glycol), poly(propyleneglycol), EVOH, pentaerithritol PVOH, polyvinylpyrollidine,vinylpyrollidone or poly(N-methyl pyrollidone), and saccharide basedcompounds, glucose, fructose, and their alcohols, mannitol, dextrin, andhydrolized starch and mixtures thereof; and a releasing agent selectedfrom the group consisting of fragrance, flavor and perfume sources;wherein the composition comprises at least three phases and hasinterconnecting channels with the releasing agent in or adjacent tothese channels.
 5. The article of manufacture of claim 4 wherein thepolymer is a thermoplastic.
 6. The article of manufacture of claim 4wherein the hydrophilic agent is a polyglycol.
 7. An article ofmanufacture comprising a monolithic composition formed by combining atleast the following components: a polymer having a solubility in waterbelow about 0.1% at 25° C. and atmospheric pressure; a hydrophilic agentis at least about 10% by weight of the polymer and is selected from thegroup consisting of polyglycols, poly(ethylene glycol), poly(propyleneglycol), EVOH, pentaerithritol, PVOH, polyvinylpyrollidine,vinylpyrollidone or poly(N-methyl pyrollidone), and saccharide basedcompounds, glucose, fructose, and their alcohols, mannitol, dextrin, andhydrolized starch and mixtures thereof; and a releasing agent selectedfrom the group consisting of antimicrobial, corrosion inhibitors,ripening and antiripening agents; wherein the composition comprises atleast three phases and has interconnecting channels with the releasingagent in or adjacent to these channels.
 8. The article of manufacture ofclaim 7 wherein the polymer is a thermoplastic.
 9. The article ofmanufacture of claim 7 wherein the hydrophilic agent is a polyglycol.10. An article of manufacture comprising a monolithic composition formedby combining at least the following components: a polymer having asolubility in water below about 0.1% at 25° C. and atmospheric pressure;a hydrophilic agent having a solubility in water above about 1% at 25°C. and atmospheric pressure and is at least about 10% by weight of thepolymer; and a releasing agent selected from the group consisting ofpesticides, nematocides, fungicides and rodenticides; wherein thecomposition comprises at least three phases and having interconnectingchannels with the releasing agent in or adjacent to these channels. 11.The article of manufacture of claim 10 wherein the polymer is athermoplastic.
 12. The article of manufacture of claim 10 wherein thehydrophilic agent is a polyglycol.
 13. An article of manufacturecomprising a monolithic composition formed by combining at least thefollowing components: a polymer having a solubility in water below about0.1% at 25° C. and atmospheric pressure; a hydrophilic agent having asolubility in water above about 1% at 25° C. and atmospheric pressuresand is at least about 10% by weight of the polymer; and a releasingagent selected from the group consisting of fragrance, flavor andperfume sources; wherein the composition comprises at least three phasesand having interconnecting channels with the releasing agent in oradjacent to these channels.
 14. The article of manufacture of claim 13wherein the polymer is a thermoplastic.
 15. The article of manufactureof claim 13 wherein the hydrophilic agent is a polyglycol.
 16. Anarticle of manufacture comprising a monolithic composition formed bycombining at least the following components: a polymer having asolubility in water below about 0.1% at 25° C. and atmospheric pressure;a hydrophilic agent having a solubility in water above about 1% at 25°C. and atmospheric pressure and is at least about 10% by weight of thepolymer; and a releasing agent selected from the group consisting ofantimicrobial, corrosion inhibitors ripening and antiripening agents;wherein the composition comprises at least three phases and havinginterconnecting channels with the releasing agent in or adjacent tothese channels.
 17. The article of manufacture of claim 16 wherein thepolymer is a thermoplastic.
 18. The article of manufacture of claim 16wherein the hydrophilic agent is a polyglycol.
 19. An article ofmanufacture comprising a monolithic composition comprising at least thefollowing components: (a) a polymer having a solubility in water belowabout 0.1% at 25° C. and atmospheric pressure; (b) a hydrophilic agentis at least about 10% by weight of the polymer and is selected from thegroup consisting of polyglycols, poly(ethylene glycol), poly(propyleneglycol), EVOH, pentaerithritol, PVOH, polyvinylpyrollidine,vinylpyrollidone or poly(N-methyl pyrollidone), and saccharide basedcompounds, glucose, fructose, and their alcohols, mannitol, dextrin, andhydrolized starch and mixtures thereof; and (c) a releasing agentselected from the group consisting of pesticides, nematocides,fungicides and rodenticides; wherein the composition comprises at leastthree phases and has interconnecting channels with the releasing agentin or adjacent to these channels.
 20. The article of manufacture ofclaim 19 wherein the polymer is a thermoplastic.
 21. The article ofmanufacture of claim 19 wherein the hydrophilic agent is a polyglycol.22. An article of manufacture comprising a monolithic compositioncomprising at least the following components: (a) a polymer having asolubility in water below about 0.1% at 25° C. and atmospheric pressure;(b) a hydrophilic agent is at least about 10% by weight of the polymerand is selected from the group consisting of polyglycols, poly(ethyleneglycol), poly(propylene glycol), EVOH, pentaerithritol, PVOH,polyvinylpyrollidine, vinylpyrollidone or poly(N-methyl pyrollidone),and saccharide based compounds glucose, fructose, and their alcohols,mannitol, dextrin, and hydrolized starch and mixtures thereof; and (c) areleasing agent selected from the group consisting of fragrance, flavorand perfume sources; wherein the composition comprises at least threephases and has interconnecting channels with the releasing agent in oradjacent to these channels.
 23. The article of manufacture of claim 22wherein the polymer is a thermoplastic.
 24. The article of manufactureof claim 22 wherein the hydrophilic agent is a polyglycol.
 25. Anarticle of manufacture comprising a monolithic composition comprising atleast the following components: (a) a polymer having a solubility inwater below about 0.1% at 25° C. and atmospheric pressure; (b) ahydrophilic agent is at least about 10% by weight of the polymer and isselected from the group consisting of polyglycols, poly(ethyleneglycol), poly(propylene glycol), EVOH, pentaerithritol, PVOH,polyvinylpyrollidine, vinylpyrollidone or poly(N-methyl pyrollidone),and saccharide based compounds, glucose, fructose, and their alcohols,mannitol, dextrin, and hydrolized starch and mixtures thereof; and (c) areleasing agent selected from the group consisting of antimicrobial,corrosion inhibitors, ripening and antiripening agents; wherein thecomposition comprises at least three phases and has interconnectingchannels with the releasing agent in or adjacent to these channels. 26.The article of manufacture of claim 25 wherein the polymer is athermoplastic.
 27. The article of manufacture of claim 25 wherein thehydrophilic agent is a polyglycol.
 28. An article of manufacturecomprising a monolithic composition comprising at least the followingcomponents: (a) a polymer having a solubility in water below about 0.1%at 25° C. and atmospheric pressure; (b) a hydrophilic agent having asolubility in water above about 1% at 25° C. and atmospheric pressureand is at least about 10% by weight of the polymer; and (c) a releasingagent selected from the group consisting of pesticides, nematocides,fungicides and rodenticides; wherein the composition comprises at leastthree phases and having interconnecting channels with the releasingagent in or adjacent to these channels.
 29. The article of manufactureof claim 28 wherein the polymer is a thermoplastic.
 30. The article ofmanufacture of claim 28 wherein the hydrophilic agent is a polyglycol.31. An article of manufacture comprising a monolithic compositioncomprising at least the following components: (a) a polymer having asolubility in water below about 0.1% at 25° C. and atmospheric pressure;(b) a hydrophilic agent having a solubility in water above about 1% at25° C. and atmospheric pressure and is at least about 10% by weight ofthe polymer; and (c) a releasing agent selected from the groupconsisting of fragrance, flavor and perfume sources; wherein thecomposition comprises at least three phases and having interconnectingchannels with the releasing agent in or adjacent to these channels. 32.The article of manufacture of claim 31 wherein the polymer is athermoplastic.
 33. The article of manufacture of claim 31 wherein thehydrophilic agent is a polyglycol.
 34. An article of manufacturecomprising a monolithic composition comprising at least the followingcomponents: (a) a polymer having a solubility in water below about 0.1%at 25° C. and atmospheric pressure; (b) a hydrophilic agent having asolubility in water above about 1% at 25° C. and atmospheric pressureand is at least about 10% by weight of the polymer; and (c) a releasingagent selected from the group consisting of antimicrobial, corrosioninhibitors ripening and antiripening agents; wherein the compositioncomprises at least three phases and having interconnecting channels withthe releasing agent in or adjacent to these channels.
 35. The article ofmanufacture of claim 34 wherein the polymer is a thermoplastic.
 36. Thearticle of manufacture of claim 34 wherein the hydrophilic agent is apolyglycol.